Method for preparing copper chloride dihydrate

Abstract

The invention provides a method for preparing copper chloride dihydrate, which comprises the following steps: S1, dissolving copper salt in a hydrochloric acid aqueous solution to obtain a first solution; s2, adding H2O2 into the first solution, then adding UiO-66-NH2, uniformly mixing, and centrifuging to obtain a supernatant; and S3, filtering the supernate, and carrying out vacuum concentration, decompression and hot dissolution, cooling crystallization, centrifugal filtration and vacuum drying on the obtained filtrate to obtain the copper chloride dihydrate. According to the method disclosed by the invention, the impurity arsenic can be effectively removed by adopting UiO-66-NH2, and new impurities are not introduced. And meanwhile, the UiO-66-NH2 can be recycled, so that the production cost is reduced. According to the method, the technological process is simplified, the equipment requirement is reduced, meanwhile, the high purity and safety of the product are ensured, the arsenic content is remarkably reduced, the medicinal standard is met, and the production efficiency and the environmental protection level are remarkably improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of preparation of copper chloride dihydrate, and particularly relates to a method for preparing copper chloride dihydrate. BACKGROUND

[0002] At present, the route for producing copper chloride dihydrate is that copper-containing materials are oxidized into cupric oxide by an oxidizing agent (chlorine, hydrogen peroxide or nitric acid), and then reacted with hydrochloric acid to obtain copper chloride dihydrate by concentration and crystallization. This method is relatively complicated and is not suitable for industrial production. In addition, there is also a method for obtaining copper chloride dihydrate by dissolving and crystallizing anhydrous copper chloride and basic copper chloride through the addition of acid. The copper chloride dihydrate obtained by this method meets the requirements of industrial chemical raw materials, but does not meet the requirements of medical raw material synthesis. There is also a method for obtaining copper chloride dihydrate by using copper sulfate solution and barium chloride or copper carbonate and hydrochloric acid solution through the principle of double decomposition. The relative equipment conditions are harsh, and the safety and environmental protection requirements are high.

[0003] The traditional method for preparing copper chloride dihydrate has problems such as many impurities and low efficiency, and cannot meet the requirements of pharmaceutical grade.

[0004] The traditional method for preparing copper chloride dihydrate is to directly react cupric oxide with hydrochloric acid, and then evaporate and crystallize to obtain copper chloride dihydrate. The raw material copper often contains impurities such as arsenic, antimony and bismuth, which are dissolved together with copper in the acid dissolution process. It is difficult to remove the impurities deeply through conventional neutralization-precipitation or recrystallization, resulting in a high content of arsenic impurities in the product, which cannot meet the requirements of high-purity copper chloride dihydrate. At the same time, repeated recrystallization reduces the yield and increases the waste liquid. Although subsequent improvements such as sulfidation for arsenic removal and electrolytic purification are made, the process is long, the cost is high, and new sulfur impurities or metal ions are easily introduced. Therefore, it has become a technical bottleneck to be broken through in the field to develop a method for preparing copper chloride dihydrate with strong raw material adaptability, simple process, efficient inhibition of arsenic co-dissolution and one-step deep purification. SUMMARY

[0005] Therefore, the present application provides a method for preparing copper chloride dihydrate, which can effectively remove arsenic and improve the purity of copper chloride dihydrate without introducing new impurities.

[0006] The technical scheme of the present application is implemented as follows: In a first aspect, the present application provides a method for preparing copper chloride dihydrate, comprising the following steps: S1, dissolving a copper salt in an aqueous hydrochloric acid solution to obtain a first solution; S2, adding H2O2 to the first solution, then adding and mixing UiO-66-NH2, and then centrifuging to obtain a supernatant; S3, filtering the supernatant, concentrating the obtained filtrate under reduced pressure, dissolving it under reduced pressure while hot, cooling and crystallizing, centrifuging and filtering, and drying under reduced pressure to obtain copper chloride dihydrate.

[0007] The application effectively removes heavy metal impurities arsenic in raw materials by using UiO-66-NH2, and does not introduce new impurities, and can be recycled.

[0008] On the basis of the above technical scheme, further, the copper salt includes any one of copper oxide and copper hydroxide. H2O2 is added to convert trivalent arsenic to pentavalent arsenic, so that arsenic is more easily adsorbed by UiO-66-NH2.

[0009] On the basis of the above technical scheme, further, the mass ratio of UiO-66-NH2 to copper is (2.5-5):1.

[0010] On the basis of the above technical scheme, further, the molar ratio of H2O2 to copper is (10-15):1.

[0011] On the basis of the above technical scheme, further, the mass fraction of the hydrochloric acid aqueous solution is 30%-35%, and the molar ratio of copper to HCl is 1:(2-3).

[0012] On the basis of the above technical scheme, further, the temperature of the reduced pressure concentration is 75-85 DEG C, and the vacuum degree is ≤-0.095 Mpa.

[0013] On the basis of the above technical scheme, further, the method for filtering the supernatant in step S3 is to filter the supernatant through a filter membrane of 0.22 μM.

[0014] On the basis of the above technical scheme, further, the temperature of the cooling crystallization is 2-8 DEG C, and the time is 6-8 h.

[0015] On the basis of the above technical scheme, further, the vacuum degree of the reduced pressure drying is ≤-0.1 MPa, and the temperature is 40-60 DEG C.

[0016] Compared with the prior art, the application has the following beneficial effects: (1) The application simplifies the process flow, reduces the equipment requirements, and at the same time ensures the high purity and safety of the product, significantly reduces the content of arsenic, meets the pharmaceutical standards, significantly improves the production efficiency and environmental protection level. The method not only reduces the production cost, but also avoids the complex operation and high pollution risk in the traditional process, realizes green and environmental protection production, and provides reliable raw material guarantee for the pharmaceutical industry.

[0017] (2) The application uses UiO-66-NH2 to effectively remove impurities arsenic, and does not introduce new impurities. At the same time, UiO-66-NH2 can be recycled to reduce production cost. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0019] In the following specific embodiments, unless otherwise specified, the experimental reagents and equipment are commercially available reagents and equipment.

[0020] In the following specific embodiments, UiO-66-NH2 is purchased from Leyou Reagent, and the item number is 1182256.

[0021] Example 1 The present embodiment provides a method for preparing copper chloride dihydrate, wherein the copper salt is copper oxide, the mass is 16.0 g, the mass fraction of the aqueous hydrochloric acid solution is 32%, and the molar ratio of copper to HCl is 1:2.4. The molar ratio of H2O2 to copper is 12:1. UiO-66-NH2 is 38.4 g, and the mass ratio of UiO-66-NH2 to copper is 3:1.

[0022] The method comprises the following steps: S1, copper oxide is dissolved in an aqueous hydrochloric acid solution, stirred at 25°C for 2h, and a transparent blue solution is obtained as a first solution; S2, H2O2 is added to the first solution, then UiO-66-NH2 is added, stirred, and then centrifuged at a speed of 12000 rpm for 10 min to obtain a supernatant; S3, the supernatant is filtered through a filter membrane with a pore size of 0.22 um, the filtrate is transferred to a rotary evaporator at 80°C, -0.1 MPa, concentrated, until a large amount of crystals are precipitated, the vacuum is released, and the solution is heated at 80°C until all the crystals are dissolved; the solution is cooled to 6°C in a cold trap, and the temperature is kept constant for 6h with stirring.

[0023] The filter cake is dried under reduced pressure at a vacuum degree of -0.1 MPa and 50°C for 5 hours to obtain finished copper chloride dihydrate.

[0024] Example 2 The present embodiment provides a method for preparing copper chloride dihydrate, wherein the copper salt is copper hydroxide, the mass is 16.0 g, the mass fraction of the aqueous hydrochloric acid solution is 30%, and the molar ratio of copper to hydrochloric acid is 1:2. The molar ratio of H2O2 to copper is 10:1. UiO-66-NH2 is 26.0 g, and the mass ratio of UiO-66-NH2 to copper is 2.5:1.

[0025] comprising the following steps: S1, copper hydroxide is dissolved in hydrochloric acid aqueous solution, stirring at 30℃ for 2h, to obtain a transparent blue solution as a first solution; S2, H2O2 is added to the first solution, then UiO-66-NH2 is added and mixed, and then centrifuged at a speed of 12000rpm for 10min to obtain a supernatant; S3, the supernatant is filtered through a filter membrane with a pore size of 0.22um, and the filtrate is transferred to a rotary evaporator at 75℃ and-0.098MPa, and concentrated until a large amount of crystals are precipitated, and the vacuum is released, and the solution is heated at 75℃ until all the crystals are dissolved; the solution is cooled to 2℃ in a cold trap and kept stirring for 7h, and then filtered.

[0026] The filter cake is dried under reduced pressure at a vacuum degree of-0.1MPa and 40℃ for 5.5h to obtain finished product copper chloride dihydrate.

[0027] Example 3 The example provides a method for preparing copper chloride dihydrate, wherein the copper salt is copper oxide, the mass is 16.0g, the mass fraction of hydrochloric acid aqueous solution is 35%, and the molar ratio of copper to hydrochloric acid is 1:3; The molar ratio of H2O2 to copper is 15:1; UiO-66-NH2 is 64.0g, and the mass ratio of UiO-66-NH2 to copper is 5:1.

[0028] comprising the following steps: S1, copper oxide is dissolved in hydrochloric acid aqueous solution, stirring at 35℃ for 2h, to obtain a transparent blue solution as a first solution; S2, H2O2 is added to the first solution, then UiO-66-NH2 is added and mixed, and then centrifuged at a speed of 12000rpm for 10min to obtain a supernatant; S3, the supernatant is filtered through a filter membrane with a pore size of 0.22um, and the filtrate is transferred to a rotary evaporator at 85℃ and-0.095MPa, and concentrated until a large amount of crystals are precipitated, and the vacuum is released, and the solution is heated at 85℃ until all the crystals are dissolved; the solution is cooled to 8℃ in a cold trap and kept stirring for 8h, and then filtered.

[0029] The filter cake is dried under reduced pressure at a vacuum degree of-0.1MPa and 60℃ for 4.5h to obtain finished product copper chloride dihydrate.

[0030] Comparative Example 1 The difference between the comparative example 1 and the example 1 is that the comparative example does not add H2O2 and UiO-66-NH2.

[0031] Comparative Example 2 The difference between the present comparative example 1 and example 1 is that the present comparative example does not add H2O2.

[0032] Comparative example 3 The difference between the present comparative example 1 and example 1 is that the mass ratio of UiO-66-NH2 to copper is 1:1.

[0033] Comparative example 4 The difference between the present comparative example 1 and example 1 is that the mass ratio of UiO-66-NH2 to copper is 10:1.

[0034] Comparative example 5 The difference between the present comparative example 1 and example 1 is that the molar ratio of H2O2 to copper is 1:1.

[0035] Comparative example 6 The difference between the present comparative example 1 and example 1 is that the molar ratio of H2O2 to copper is 100:1.

[0036] Performance detection The instrument inductively coupled plasma emission spectrometer is used to detect the copper chloride dihydrate and its main impurities in examples 1-3 and comparative examples 1-6. The detection results are shown in the following table 1. GB / T 15901-2021 analytical pure requires that the content of arsenic in copper chloride dihydrate is ≤0.0002%, and the content of nickel is ≤0.001%.

[0037] Table 1 Detection results of copper chloride dihydrate and impurities

[0038] As can be seen from table 1, the copper chloride dihydrate prepared by the present application has high purity, and the contents of heavy metal ions nickel and arsenic are less than the standard required by GB / T 15901-2021 analytical pure. However, in comparative example 1, without adding H2O2 and UiO-66-NH2, the ability to remove arsenic is limited, and the content of arsenic is high. In comparative example 2, without adding H2O2, there is more trivalent arsenic in the solution, and the adsorption force of UiO-66-NH2 to pentavalent arsenic is high, but the adsorption capacity to trivalent arsenic is weak, so the content of arsenic in comparative example 2 is high. In comparative example 3, the mass ratio of UiO-66-NH2 to copper is too small, so the adsorption effect of UiO-66-NH2 is limited, and the effect of removing arsenic is weak. In comparative example 4, the content of UiO-66-NH2 is too high, which will lead to the loss of Cu 2+ , thereby reducing the content of copper chloride dihydrate and increasing the content of arsenic. In comparative examples 5 and 6, the molar ratio of H2O2 to copper is too small or too high, which will lead to the formation of complex of Cu 2+ , thereby reducing the content of copper chloride dihydrate and increasing the content of arsenic.

[0039] In summary, the method for preparing copper chloride dihydrate has the advantages of simplifying the process, reducing the production cost, and significantly improving the purity and safety of the product, and fully meets the pharmaceutical standards. The high efficiency and environmental protection characteristics of the method not only bring economic benefits to enterprises, but also make positive contributions to environmental protection, and have wide application prospect and development potential.

[0040] The above merely describes preferred embodiments of the present application and is not intended to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing copper chloride dihydrate, characterized in that, Includes the following steps: S1. Copper salt is dissolved in hydrochloric acid aqueous solution to obtain the first solution; S2. Add H2O2 to the first solution, then add UiO-66-NH2, mix well, and centrifuge to obtain the supernatant. S3. Filter the supernatant, concentrate the obtained filtrate under reduced pressure, dissolve it while hot after depressurization, cool it to crystallize, centrifuge and filter it, and dry it under reduced pressure to obtain copper chloride dihydrate.

2. The method for preparing copper chloride dihydrate as described in claim 1, characterized in that, The copper salt includes either copper oxide or copper hydroxide.

3. The method for preparing copper chloride dihydrate as described in claim 1, characterized in that, The mass ratio of UiO-66-NH2 to copper is (2.5~5):

1.

4. The method for preparing copper chloride dihydrate as described in claim 1, characterized in that, The molar ratio of H2O2 to copper is (10~15):

1.

5. The method for preparing copper chloride dihydrate as described in claim 1, characterized in that, The hydrochloric acid aqueous solution has a mass fraction of 30%~35%, and the molar ratio of copper to HCl is 1:(2~3).

6. The method for preparing copper chloride dihydrate as described in claim 1, characterized in that, The vacuum concentration temperature is 75~85℃, and the vacuum degree is ≤-0.095Mpa.

7. The method for preparing copper chloride dihydrate as described in claim 1, characterized in that, The cooling crystallization temperature is 2~8℃, and the time is 6~8h.

8. The method for preparing copper chloride dihydrate as described in claim 1, characterized in that, The vacuum degree of the vacuum drying is ≤-0.1MPa, and the temperature is 40~60℃.

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